Conventional jet transport aircraft typically include movable control surfaces on both the leading and trailing edges of the wing. Common leading edge devices include slats and flaps, and common trailing edge devices include flaps, spoilers, and ailerons. Slats, flaps, and spoilers are typically used for aircraft control during slow flight (e.g., during take-off and landing), while ailerons provide roll control during all phases of flight.
Gaps between trailing edge control surfaces and the wing can cause aerodynamic drag that reduces aircraft performance. In commercial aircraft, the reduction in performance can equate to a significant increase in fuel consumption over the life of the aircraft. One conventional approach for sealing these gaps is to install a piece of fabric between the trailing edge of the wing and the leading edge of the control surface.
One drawback of conventional fabric seals, however, is that the fabric material is generally so compliant that it tends to flutter as the control surface moves relative to the wing. This flutter causes aerodynamic drag that can reduce aircraft performance. Another drawback of this approach is that conventional fabric seals are generally too flexible to form a smooth transition between the wing and the control surface at various control surface positions. Abrupt transitions on the wing surface can also cause unwanted aerodynamic drag. A further drawback of conventional fabric seals is that they tend to wear rapidly. As a result, they must be inspected and/or replaced frequently.